Worst club in Europe, by default
Also, as the son on an amaeur photographer, when it comes to taking photos it's all about atmosphere. They are quite a biased medium. The photographer probably wanted to express the tranquilty of Durham, so chose to take the photographs at a time when few people were around. This, for example: -

OK, not the greatest example, but I don't have time to search for something better. I'm sure people get my point though. It wouldn't have had quite the same effect if there were crowds (or even just a handful) of people.
Durham's probably one of the most photographed cities outside London (I read that somwhere, just beleive it

) and the vast majority of them are going to be of tranquil scenes by the river bed, the cathedral and Old Fulling Mill, the Bailey etc. But, on the other hand, you don't get many of these


Again, not the best examples I can find.
With 40,000 permanent residents (used to have the largest private housing estate in Europe, goodness knows why) and 18,000 students it makes for a fair number of people in such a small city.
So if you're talking about how "busy" the city looks, I can assure you that you often can't move for fellow pedestrians. With so many locals and students in such a small city, it's quite budy in Market Square and the major streets.
I don't think any university or city, that has thousands of students, is "dead" or boring. It just depends on what you're after.
Edit: -
Whilst searching for those photos (all from the BBC) I came across this one

My daddy took that! April 2004's photograph of the month winner. Nothing to do with Durham, I'd just forgotten about it.